Display panel and methods of manufacture



Sept. 5, 1967 E. H. DORIS ETAL DISPLAY PANEL AND METHODS OF MANUFACTURE Filed Feb. 7, 1966 ZR wee -20 A A H w E0 5 9 a 9 M gm QTTURNEY United States Patent Filed Feb. 7, 1966, Ser. No. 536,489 2 Claims. (Cl. 40-142) This invention relates to a new and improved type of display panel having grooves for receiving tab portions of various types of interchangeable symbols such as numerals or letters of the alphabet, for use in building directories, hotel signs, signs in general, menus in restaurants, and sales and production control charts. The invention also includes new and improved methods of manufacture of such display panels.

Conventional grooved display panels are made from wood materials such as plywood as a base, over which a covering of cloth or plastic material is placed in a separate operation. Such conventional display panels are difficult to manufacture because the grooves in such display panels must be cut by a saw, which requires substantial time and trouble where a relatively large number of grooves are required, as in the case of a display panel.

Further, the covering placed over such conventional display panels must be forced into the grooves individaual- 1y with a roller or other means, which requires substantial time to perform.

Finally, besides being relatively expensive to construct such conventional display panels are relatively heavy in weight since plywood ranging from /2 to 4 inch in thickness is conventionally used in the construction of such conventional display panels. Transportation charges are thus an additional expense to consider besides the relatively high cost of construction of such conventional display panels, due to the relatively high cost of the materials used and the labor required.

It is, therefore, an object of this invention to provide a display panel which is capable of being produced from relatively inexpensive raw materials.

Another object of this invention is to provide 'a display panel which is relatively easy to manufacture in a completed form ready for use in one operation.

A further object of this invention is to provide methods of manufacture of such display panels at relatively low cost.

A still further object of this invention is to provide a display panel which is relatively light in weight and easily transported.

A yet further object of this invention is to provide a display panel which has no component parts required to be added to it before it can be used by the ultimate consumer.

These and other objects will be more readily understood by reference to the following description and claims, taken in conjunction with the accompanying drawing, in which FIGURE 1 is a front elevational view of the display anel. p FIGURE 2 is a view taken along line 22 of FIG- URE 1.

FIGURE 3 is a perspective view of a section of a modified form of the display panel, illustrating the grooves formed therein.

The display panel is produced by forming raw plastic having resilient qualities into a single sheet of resilient plastic material having a series of parallel grooves preformed thereon. Various plastic materials may be such as polystyrene foam, polyethylene foam, expanded polyurethane, and similar resilient plastics capable of being molded or extruded. Such plastic materials may be of various colors or color impregnated.

Such raw plastic material is extruded or otherwise formed into a fiat sheet having a series of parallel grooves in a single operation by a die, mold or other suitable tooling. The following is an example of a method of man-ufacturing a display panel embodying our invention by use of a die.

Example 1 Liquid polyethylene foam is the raw plastic material used. It is heated to a temperature of approximately 350 F. to 400 F. and is then extruded through a die of the desired cross section, said die having an internal configuration such that it produces a series of horizontal parallel grooves into the plastic material as it goes through the die.

The die must also be elongated sufiiciently to allow the hot plastic material to cool and set, thereby maintaining its dimensional stability. Such an elongated die will also keep the walls of the parallel grooves separated until the plastic material has cooled sufliciently to prevent adhesion together of the walls of the parallel grooves.

The resulting product is a display panel formed from plastic material and having a series of horizontal parallel grooves formed integrally in the plastic material in a single operation.

Where necessary, an additional step may be included in the method of Example 1 to prevent the hot plastic material from adhering to the die as the cooling process takes place. Such a step comprises coating the surface of the die with a fluorocarbon material such as Teflon which has a higher melting point than the temperatures used in Example 1 :and a low coeflicient of friction. The following Example 2 illustrates this step.

Example 2 A method of preparing a display panel having a series of parallel grooves formed therein according to Example 1, with an additional step of first coating the surface of the elongated die with a fluorocarbon material having a low coeflicient of friction and a higher melting point than the plastic material used to form the display panel.

A still further method of preparing the Display Panel is obtained by the use of an array of fine wires, still in a single operation. This method requires the use of an array of parallel wires approximately 4 inch apart. We have found that suitable wires for this method may be made of steel of about inch diameter. The following Example 3 illustrates the use of this method.

Example 3 An array of 192 wires, each 8 feet long and having a diameter of inch, placed parallel to each other, were stretched tight within a frame to form an array 8 feet long and 4 feet wide. The wires were heated to approximately 450 F. by passing an electric current through them. The wire array was then lowered over a sheet of plastic foam stock such as polyethylene foam of any convenientsize smaller in area than 4 by 8 feet. The hot wires are then lowered so as to cut into the plastic foam causing parallel grooves to be formed. Since the plastic stock material used is selected with a surface of desired texture, a finished display operation from a suitable plastic raw stock material.

Extrusion methods or other types of tooling may be selected to produce a similar fiat plastic sheet having similar horizontal parallel grooves 12 formed into the material itself on one side.

After being thus formed, the grooved plastic sheet is then cut to a standard or other desired size, for immediate use as a display panel for receiving characters or symbols such as letters 14 or numerals with tabs 16 capanel is thus formed in a single pable of being inserted into the grooves 12. The resilience of the plastic material maintains pressure against the tabs 16, thereby keeping tabs of the characters in position.

Although a frame or molding 18 of aluminum or other suitable material may be attached to the edges of the display panel for the sake of appearance, the display may be used with or without the frame or molding 18.

The grooves 12 and 12a are preferably formed with straight parallel sides and of a width narrower than the tabs of the symbols to be inserted.

The display panel so produced is relatively light in weight, complete in itself without the need for adding other components, and ready for immediate use.

The plastic material used in the manufacture of the display panel may be easily cut with a knife or razor or other cutting implement so that various sizes for the display panel may be readily obtained.

Further, the plastic material of the display panel is easily cleaned and is moisture resistant.

Finally, the display panel can be manufactured with grooves on both sides by the use of a suitable die or extnusion procedure or other suitable tooling as well as the hot wire method. Conventional display panels must be joined back to back to produce a display panel with grooves on both of its sides.

Although we have described our invention in detail with reference to preferred embodiments of products and methods of manufacture, it is understood that numerous changes in the details of construction as well as changes in the steps of the methods may be made without departing from the spirit and scope of the invention as described and hereinafter claimed.

We claim:

1. In a sign assembly comprising a display panel and a plurality of indicia elements adapted to be disposed in horizontal rows thereon, said elements being substantially rigid and having rigid parallel tab portions extending rearwardly from their upper and lower extremities to define a generally U-shaped configuration in cross-section, the improvement consisting of said display panel comprising an integral, relatively thick slab of solid resilient foam plastic material having on one side thereof parallel grooves extending inwardly from the outer surface of said one side toward a central plane of said slab parallel to said outer surface and terminating at points disposed in a plane spaced inwardly from the opposite sides of said slab, said grooves being narrower in cross-section than said tab portions and being defined by straight parallel side walls having resilient, closely spaced, opposed surfaces for receiving and gripping said tab portions, whereby various indicia elements may be firmly but removably mounted in selected positions on said outer surface.

2. A sign assembly as defined in claim 1 wherein said parallel grooves are formed on both sides of said display panel.

References Cited UNITED STATES PATENTS 2,677,747 5/ 1954 Jaye 264-22 2,879,614 3/1959 Baldanza -140 X 2,880,537 4/1959 Cygan 40140 X 2,966,754 1/1961 Orkin 40 3,190,943 6/1965 Santelli 264-448 EUGENE R. CAPOZIO, Primary Examiner.

S. M. BENDER, Examiner.

R. W. WEIG, Assistant Examiner. 

1. IN A SIGN ASSEMBLY COMPRISING A DISPLAY PANEL AND A PLURALITY OF INDICIA ELEMENTS ADAPTED TO BE DISPOSED IN HORIZONTAL ROWS THEREON, SAID ELEMENTS BEING SUBSTANTIALLY HORIZONTAL ROWS THEREON, SAID ELEMENTS BEING SUBSTANTIALLY RIGID AND HAVING RIGID PARALLEL TAB PORTIONS EXTENDING REARWARDLY FROM THEIR UPPER AND LOWER EXTREMITIES TO DEFINE A GENERALLY U-SHAPED CONFIGURATION IN CROSS-SECTION, THE IMPROVEMENT CONSISTING OF SAID DISPLAY PANEL COMPRISING AN INTEGRAL, RELATIVELY THICK SLAB OF SOLID RESILIENT FOAM PLASTIC MATERIAL HAVING ON ONE SIDE THEREOF PARALLEL GROOVES EXTENDING INWARDLY FROM THE OUTER SURFACE OF SAID ONE SIDE TOWARD A CENTRAL PLANE OF SAID SLABS PARALLEL TO SAID OUTER SURFACE AND TERMINATING AT POINTS DISPOSED IN A PLANE SPACED INWARDLY FROM THE OPPOSITE SIDES OF SAID SLAB, SAID GROOVES BEING NARROWER IN CROSS-SECTION THAN SAID TAB PORTIONS AND BEING DEFINED BY STRAIGHT PARALLEL SIDE WALLS HAVING RESILIENT, CLOSELY SPACED, OPPOSED SURFACES FOR RECEIVING AND GRIPPING SAID TAB PORTIONS, WHEREBY VARIOUS INDICIA ELEMENTS MAY BE FIRMLY BUT REMOVABLY MOUNTED IN SELECTED POSITIONS ON SAID OUTER SURFACE. 